Milzman Dave, Napoli Anthony, Hogan Christopher, Zlidenny Alex, Janchar Tim
Department of Emergency Medicine, Georgetown University Medical Center and Washington Hospital Center, Washington, DC 20010, USA.
Am J Emerg Med. 2009 Sep;27(7):770-5. doi: 10.1016/j.ajem.2008.06.002.
We sought to investigate the relationship between thoracic impedance (Zo) and pulmonary edema on chest radiography in patients presenting to the emergency department (ED) with signs and symptoms of acute decompensated heart failure (ADHF).
This was a prospective, blinded convenience sample of patients with signs and symptoms of ADHF who underwent measurement of Zo with concomitant chest radiography. Attending physicians blinded to the Zo values interpreted the radiographs, categorizing the severity of pulmonary edema as normal (NL), cephalization (CZ), interstitial edema (IE), or alveolar edema (AE). Intergroup comparisons were analyzed with a 2-way analysis of variance (ANOVA), with P < .05 considered statistically significant and reported using 95% confidence intervals (CIs).
We enrolled patients (> or =18 years) presenting to a tertiary care medical center ED with signs and symptoms consistent with ADHF.
A total of 203 patients were enrolled, with 27 (14%) excluded because of coexisting pulmonary diseases. The mean Zo values were inversely related to the 4 varying degrees of radiographic pulmonary vascular congestion as follows: NL, 25.6 (95% CI, 22.9-28.3); CZ, 20.8 (95% CI, 18.1-23.5); IE, 18.0 (95% CI, 16.3-19.7); and with AE, 14.5 (95% CI, 12.8-16.2) (ANOVA, P < .04). A Zo less than 19.0 ohms had 90% sensitivity and 94% specificity (likelihood ratio [LR], - 0.1; LR + 15) for identifying radiographic findings consistent with pulmonary edema. Females had an increased mean Zo value compared to males (P < .03).
The Zo value obtained via thoracic bioimpedance monitoring accurately predicts the presence and severity of pulmonary edema found on initial chest radiograph in patients suspected of ADHF.
我们试图研究急诊科（ED）中出现急性失代偿性心力衰竭（ADHF）体征和症状的患者的胸阻抗（Zo）与胸部X线片上肺水肿之间的关系。
这是一项前瞻性、盲法便利样本研究，对有ADHF体征和症状的患者进行Zo测量，并同时拍摄胸部X线片。对Zo值不知情的主治医生解读X线片，将肺水肿严重程度分为正常（NL）、肺血重新分布（CZ）、间质性水肿（IE）或肺泡性水肿（AE）。采用双向方差分析（ANOVA）进行组间比较，P <.05被认为具有统计学意义，并使用95%置信区间（CI）报告。
我们纳入了在三级医疗中心急诊科就诊、有与ADHF一致的体征和症状的患者（年龄≥18岁）。
共纳入203例患者，其中27例（14%）因并存肺部疾病而被排除。平均Zo值与胸部X线片上4种不同程度的肺血管充血呈负相关，如下：NL为25.6（95%CI，22.9 - 28.3）；CZ为20.8（95%CI，18.1 - 23.5）；IE为18.0（95%CI，16.3 - 19.7）；AE为14.5（95%CI，12.8 - 16.2）（ANOVA，P <.04）。Zo小于19.0欧姆对识别与肺水肿一致的X线片表现具有90%的敏感性和94%的特异性（似然比[LR]，- 0.1；LR + 15）。女性的平均Zo值高于男性（P <.03）。
通过胸生物阻抗监测获得的Zo值能准确预测疑似ADHF患者初始胸部X线片上肺水肿的存在及严重程度。
